according to nasa, there could be as much as 1 million metric tons of ice on the planet. why should this matter to us? >> well, it's, of course, a big surprise. although, some people thought there might be ice in the deep craters on mercury. mercury has very little tilt, unlike the earth, which is tilted. that means that the north pole is essentially never pointing towards the sun. if the deep craters get near the north pole, those never get sunlight. in fact, that's where the ice is found. the other interesting thing is the the ice is covered by a little layer of organic material. that's probably because the ice was probably delivered by comets, the same way the water on earth was probably delivered to earth. that makes it interesting because you have water and organic material. it's not the best place to look for life. you wouldn't want to choose mercury over any other place. what it means is even the most extreme environment in the solar system, mercury, which goes from this incredible heat to this incredible cold, has water and organic material.